Universal drill-shaft



S. P. DAHL. UNIVERSAL DRILL SHAFT.

(Nb'Model.)

No. 543,083. Patented July 23,1895.

' UNITED STATES f PATENT? GEEICE.

- lVIAlBTGrNUS SIP. DAHL, OF CHIAGO, ILLINOIS.

UNIVERSAL DRILL=SHAFT.

SPECIFICATION forming part of Letters Patent No. 543,083, dated July 23, 1895. v

Application filed March 5, 1895. Serial No. 540,585. (No modali) T all whom, t may concern.'

Be it known that LMANGNUs S. P. DAHL, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Universal Drill-Shafts, fully set forth in the following specification, reference being had to the accompanying drawings, forming a part hereof, in which- Figure l shows a central longitudinal section of all the parts surrounding the shafts, the latter being shown entire. Fig. 2 shows the under side of a Washer, of which Fig. 3 shows the same in elevation. Fig. 4 shows a central longitudinal section of a gear adapted for the washer or plate shown in the two preceding flgures. Fig. 5 shows a connector or coupler whichconnects my device with any suitable driving device.

Like letters of reference refer to like parts. The object of my invention is to construct a drill-shaft for dentists drills or other uses, in which the drill may point in every direction of a complete circle and sphere, wherein the drill-shaft is in a case which moves with it,

' but is free from its axial motion, and also free from all resisting strain when moved from 'place to place and from all other vibrations and consequent uncertainty of direction while in action. To attain said desirable ends I construct my said new device in substantially the following manner, namely: v 4

I place the shafts b c d, connected with miter-gears a a', and inclose them in the double shells e e' f f and the treble shells g-g g2 and elbows h h', of which the shells ej, and g are conne'cted vby screw-threaded coupling ends e2 f2 g3 to said elbows, substantially as shown. The shell e is chambered at the end which unites with the elbow to receive the flanged end of the shell e', within which turns the shaft b, and is held in placeby it and its miter-wheel. The shell f is likewise chambered at the end which joins the elbow h to receive the flanged shell f within it. The shell f has a ring f3, screw-threaded on its other end,l

forming a flange thereon, with a threaded extension which screws into the elbow 71.. The shellfhas a free sliding joint on the flange f3. By said construction said shells f and f turn upon each other and on the shaft c, thus permitting the axes of the shafts b and d to point in every direction of a complete circle. The end of the shell g has a threaded extension g3, which is chambered to receive the flanged end ofthe shell g2, and mitergear on shaft d, and near its outer end is a circumferential groove g4, into which is depressed the correspondingly-grooved shell g, the end of which forms a free moving` joint against the flange of the shell g', thus securing said shells revolubly vupon each other.

One of each pair of gears is ofrawhide to make them as n'oiscless as possible and to hold them upon the shaft. i A ribbed ange or plate j, withnotches t" to tit upon the pins i, isput one on each shaft. The rib j enters a groove j? of the gear, thus holding-it from turning on its/shaft. Y

The slotsZ in the chamberedend of the shaft d receive the lugs 'i2 of the connector 7a, through which these shafts are connected with the tool-holder screwed into the threaded end of the shell g.

. The' end n of the shafth screws into the connecting device of a flexible shaft or any like device. By means of this construction the drill may be held securely and steadily to any point in any direction whatever.

The shell f turns with the elbow h', and the shell f with the elbow h, and the shell g with the tool-holder or chuck screwed fast into its open end.

The combination with three end-connected shafts, whereof two revolve in their planesA 

